I decided to share my Cunningham 1932 tube handbook. It was copyrighted but the US copyright law state that work with published with notice, between 1923 and 1963. Is in the public domain if copyright was not renewed. And this is the case here no renewal. In the text file I have placed a link to my private rapidshare account. Due to the size I could not upload it here. Rapidshare is 100% safe and legal in this this case. Nothing to worry about

Thanks! I enjoy old tube books and "service tips" pamphlets. I'm not quite old enough to have repaired radios that used indicator lamps in the tube filament string, but I did work (full time) on vacuum tube TV's and hobby around a bit with guitar amplifiers. I have the GE and RCA tube manuals, but only in paper form. The circuits that were made with vacuum tubes are still examples of good engineering.

You probably already know this, but, iron was the preferred method a hundred years ago because capacitor technology was pretty primitive, like paper and beeswax. Nowadays, you can get 10uf the size of an aspirin.